Search Publications
Radiation from matter-antimatter annihilation in the quark nugget model of dark matter
Flambaum, V. V.; Samsonov, I. B.
We revisit the properties of positron cloud in quark nugget (QN) model of dark matter (DM). In this model, dark matter particles are represented by compact composite objects composed of a large number of quarks or antiquarks with total baryon number B ∼1024. These particles have a very small number density in our galaxy which makes them…
Constraints on chameleon gravity from the measurement of the electrostatic stiffness of the M I C R O S C O P E mission accelerometers
Bergé, Joel; Pernot-Borràs, Martin; Uzan, Jean-Philippe +4 more
This article is dedicated to the use the MICROSCOPE mission's data to test chameleon theory of gravity. We take advantage of the technical sessions aimed to characterize the electrostatic stiffness of MICROSCOPE's instrument intrinsic to its capacitive measurement system. Any discrepancy between the expected and measured stiffness may result from …
Constraining the Konoplya-Rezzolla-Zhidenko deformation parameters: Limits from supermassive black hole x-ray data
Tripathi, Ashutosh; Abdikamalov, Askar B.; Ayzenberg, Dimitry +2 more
X-ray reflection spectroscopy is a powerful technique for probing the nature of gravity around black holes in the so-called strong-field regime. One popular approach is to look at theory-agnostic deviations away from the Kerr solution, which is the only astrophysically relevant black hole solution within classical general relativity, in order to v…
Assessing the potential of cluster edges as a standard ruler on constraining dark energy models
Wang, Deng
We assess comprehensively the potential of galaxy cluster edges as a standard ruler in measuring cosmological distances and probing exotic physics. Confronting five alternative cosmological models with cluster edges from the near-future Dark Energy Spectroscopic Instrument survey, we conclude that cluster edges can serve as a promising probe to co…
New physics in light of the H0 tension: An alternative view
Vagnozzi, Sunny
The strong discrepancy between local and early-time (inverse distance ladder) estimates of the Hubble constant H0 could be pointing towards new physics beyond the concordance Λ CDM model. Several attempts to address this tension through new physics rely on extended cosmological models, featuring extra free parameters beyond the six Λ CD…
I N T E G R A L constraints on primordial black holes and particle dark matter
Slatyer, Tracy R.; Muñoz, Julian B.; Laha, Ranjan
The International Gamma-Ray Astrophysics Laboratory (I N T E G R A L ) satellite has yielded unprecedented measurements of the soft gamma-ray spectrum of our Galaxy. Here we use those measurements to set constraints on dark matter (DM) that decays or annihilates into photons with energies E ≈0.02 - 2 MeV . First, we revisit the constraints on part…
Cosmography in f (Q ) gravity
Wang, Deng; Sahoo, P. K.; Mandal, Sanjay
Cosmography is an ideal tool to investigate the cosmic expansion history of the Universe in a model-independent way. The equations of motion in modified theories of gravity are usually very complicated; cosmography may select practical models without imposing arbitrary choices a priori. We use the model-independent way to derive f (z ) and its der…
Can late dark energy transitions raise the Hubble constant?
Raveri, Marco; Hu, Wayne; Benevento, Giampaolo
Late times dark energy transitions at redshifts z ≪0.1 can raise the predicted value of the Hubble constant to the SH0ES value, 74.03 ±1.42 (km s-1 Mpc-1) or more, while providing an equally good fit as Λ CDM at 67.73 ±0.41 to higher redshift data, in particular from the cosmic microwave background and baryon acoustic oscilla…
Axion and neutrino bounds improved with new calibrations of the tip of the red-giant branch using geometric distance determinations
Capozzi, Francesco; Raffelt, Georg
The brightness of the tip of the red-giant branch (TRGB) allows one to constrain novel energy losses that would lead to a larger core mass at helium ignition and, thus, to a brighter TRGB than expected by standard stellar models. The required absolute TRGB calibrations strongly improve with reliable geometric distances that have become available f…
Updated constraints on asteroid-mass primordial black holes as dark matter
Profumo, Stefano; Guhathakurta, Puragra; McKinnon, Kevin +3 more
Microlensing of stars places significant constraints on subplanetary-mass compact objects, including primordial black holes, as dark matter candidates. As the lens' Einstein radius in the source plane becomes comparable to the size of the light source, however, source amplification is strongly suppressed, making it challenging to constrain lenses …